Combination drill point gauge, bevel protractor, and center head



Dec. 15, 1936. G, E 'JOHNSON 2,064,430

COMBINATION DRILL POINT GAUGE, BEVEL PROTRACTOR, AND CENTER HEAD Filed April 13, 1936 Cil Patented Dec. l5, 1 936 PATENT OFFICE/f COMBINATION DRILL POINT GAUGE, BEVEL PROTRACTOR, AND CENTER HEAD Gladwin E. Johnson, Chicago, Ill.

VAp'pliration April 13, 193s. serial No. 74,027

' s Claims'. (Cl. 3s-93 Y This invention relates to a combination drill point gauge, bevelprotractor and center head.

The main robject of the invention is to produce a very simple tool comprising only two pieces pivotally connectedtogether,A which provide a rigid gauge for measuring the angle` and length of `drill points, means forlocating the centers of round objects, andmeans for defining and measuring. angles.

The `advantages of my invention will appear from the following specification.- f

In .the drawing: I l

Fig. 1 is a plan view Ion an enlarged scale, of a combination tool yembodying my invention, showing in fulland dotted lines two positions of the pivoted r'nembe'r.Y

Fig. 2 'is a plan view ofthe device, also enlarged, with the pivoted member superimposed on the other. I

Fig. 3 is 'a transverse sectional View taken in the plane of the line 3-3 of Fig, 2.

Fig. 4 isa side viewof the tool as shown in Fig. 2.

The main member I comprises a flat piece of metal or other suitable material. Its elongated body portion has a straight edge II at one side, and a parallel, shorter straight edge I2 at the other, between which the body is provided With conventional linear measure markings, The body of the member IIJ is wider at one end than at the other, its straight edge I3 intersecting the edge I2 and extending at an angle of 121 to said edge I2. This angle was selected because conventional drill points are inclined at an angle of 59 to their axes, and therefore the correctness of a drill point may be gauged by placing one side of the drill body against the edge I2, with the point surface adjacent the edge I3, and comparing the drill point angle with the angle of said edge I3. The drill point will be reground, if necessary, so that it will be parallel with said edge I3, when the axis of the drill is parallel with the edge I2, proving the drillpoint angle is correct.

It should be understood that the disposition of the edges I2 and I3 at an angle of 121 was selected for the preferred embodiment of the invention and its adaptation to a drill point gauge, but the invention is not limited in this respect and other xed angles suitable for comparison with devices otherthan drill points may be formed by the edges I2 and I3 without departing from my invention.

The edge I3 is provided with suitablemarkings for measuring the length of the drill poi-nt or other object'to bemeasured', and preferably the division lines of the markings extend parallel to the edge I2. v

The member IIJ is provided' with 'a curved edge I4 between the edges II and I3, the center'of 5 the curve coinciding with the -pivotal point I5. Protractor markings are provided, as shown, along the curved edge I4, and a line I6 marked center head line is provided for a purpose to be described. l y A 10 The second member of the tool is indicated at I1 and it ispivotally connected to the member Il) by a countersunk: rivet I8, the center of which is the pivotal point I5. The member I1 consists of an elongated portion having straight, parallel edges I9, and a head Aportion having converging edgesl 2I, 22, forming a point 23. The particular form of the head portion and angular disposition of the edges 2|, 22, may be varied, but inthe present embodiment ,the protractor 20 markings on the edge I4, the center head line I6, and the edge 22 of the pivoted member I'I, are

so arranged that when the pivoted member is moved to the dotted line position of Fig. 1 wherein the edge 22 coincides With the line I6,\25 the point 23 will be opposite G01/2 on the protractor edge, and the edge I9 of the member I'I will then bisect the angle of .121 between the edges I2 and I3,

To use the tool as a protractor for drawing angles on paper or the like, the pivoted member I'I is moved to a position wherein the point 23 registers with the desired angle marking, as for example 90,as shown in full lines in Fig. 1. In that position, the edges I2 and I9 of the mem- 35 bers I0 and I 1, respectively, will be at a 90 angle to each other. When using the tool to measure angles, the pivoted 'member is moved until the edges I2 and I9 coincide with the lines dening the angle to be measured, and the point 40 23 will indicate the reading on the markings adjacent the edge I4. v

To use the tool as a center head for locating thecenter of a round object, such as the circle 24, the member I0 is placed so that the edges I2 4 and I3 contact the circular Wall or outline 24 and then the pivoted member II is lmoved to the dotted line position of Fig-1, with' the point 23 registering with G01/2 and the edge 22 co- 50 inciding with the center head line I6. In this position the edge I9 of the member I1 bisects the angle defined by the edges I2 and I3. By drawing a line adjacent the edge I9 across the object 24, and repeating the procedure just described after turning the object 24 about 90, the

` center of the object will be located.

`iixed angle may be, when the point 23 registers with the mark indicating one-half of that angle, the edge I9 will bisect the angle dened by the intersecting edges I2 and I3, and thus the center of a round object contacted by the edges I2 and I3 may be located.

To use the tool as a drill point gauge, the parts are preferably disposed as shown in Fig. 2, and the drill is placed against and parallel with the edge I2, the inclined surface of the point being parallel with the edge I3 or approximately so. If it is not truly parallel with said edge, the

Adrill requires regrinding. The markings on the edge I3 are used to measure thelength of the drill point.

Changes may be made in details of construction without departing from the scope of my invention and I do not intend to be limited to the exact form shown and described, except kas set` forth in the appended claims.

I claim:

1. A combination tool comprising an elongated fiat body member having two straight intersecting edges forming a xed obtuse angle at one side by the bo'dy between its ends, said angle being complemental to a drill point to be gauged, a protrac'tor scale on the end of said body, and a second elongated member having a straight edged arm and an indicator head pivotally connected in superimposed relation' to the said body, between the scale and said intersecting edges, one edgeof said arm bisecting said fixed angle on the body member at its vortex when the indicator head registers with a point on the protractor scale vdesignating a degree equal to onehalf of said angle.

2. A combination tool comprising an elongated flat body member having two straight intersecting edges forming a fixed obtuse angle at one side of the body between its ends, said angle being complemental to a drill point to-be gauged, a protractor scale on the end of said body, and a second elongated member having a straight edged arm and an indicator head pivotally connected in superimposed relation to the said body, between the scale and said intersecting edges, a center head line on the body member between the protractorscale and said pivotal connection, one edge of said arm bisecting said xed angle on the body member at its-vortex when one edge of the indicator head registers with the center head line on the body member and the indicator head registers with a point on the protractor scale designating a degree equal to one-half of said angle.

3. A combination tool comprising an elongated flat body member wider at one end than at the other and having two straight intersecting edges,

forming a fixed obtuse angle at. one side of the body between its ends, said angle being complemental to an object to be gauged, the end edge of the wider body portion being curved concentrically and provided with a protractor scale, and a second elongated member having a straight edged arm and a pointed indicator head'pivotally connected in superimposed relation to the said body axially of said protractor scale between the scale and said intersecting edges, and adapted to overlie the Ibody member entirely within the margins of said body, one edge of said arm bisect-ing said xed angle on the body member at its vortex when the indicator head registers with a point on the protractor scale designating a degree equal to one-half of said angle.

GLADWIN E. JOHNSON.r 

